import streamlit as st
from callbacks import toggle_all_video_checkboxes, callback_delete_selected_videos

@st.fragment
def video_management_fragment(paths):
    """A self-contained fragment for managing and deleting project videos."""
    with st.expander("🎬 管理專案影片素材"):
        output_dir = paths["output"]
        video_files = []
        if output_dir.exists():
            video_files = sorted(
                [f for f in output_dir.iterdir() if f.suffix.lower() in ['.mp4', '.mov']],
                key=lambda f: f.stat().st_mtime,
                reverse=True
            )

        if not video_files:
            st.info("專案輸出資料夾 (`/output`) 中目前沒有影片檔。")
        else:
            all_selected = all(st.session_state.get(f"delete_cb_{f.name}", False) for f in video_files)
            if st.session_state.get('select_all_videos', False) != all_selected:
                st.session_state.select_all_videos = all_selected

            st.markdown("勾選您想要刪除的影片，然後點擊下方的按鈕。")
            
            st.checkbox(
                "全選/取消全選", 
                key="select_all_videos", 
                on_change=toggle_all_video_checkboxes, 
                args=(video_files,)
            )
            
            with st.form("delete_videos_form"):
                for video_file in video_files:
                    file_size_mb = video_file.stat().st_size / (1024 * 1024)
                    st.checkbox(
                        f"**{video_file.name}** ({file_size_mb:.2f} MB)",
                        key=f"delete_cb_{video_file.name}"
                    )

                submitted = st.form_submit_button("🟥 確認刪除選取的影片", use_container_width=True, type="primary")
                
                if submitted:
                    callback_delete_selected_videos(paths)
                    st.rerun(scope="fragment")